1. Field of the Invention
The invention relates to a switchover device for a low capacity gas feed system of the type for use in feeding chlorine gas to a water supply to chlorinate the water. More specifically the invention relates to a switchover device for controlling gas flow from different gas supplies.
2. Related Art
Low capacity chlorine gas feed systems provide for the supply of gas from chlorine gas containers through a gas pressure regulator device to an injector wherein the chlorine gas is delivered to a water supply conduit. One chlorine feed system is illustrated in the assignee's Technical Data Sheet 910.250 titled "SONIX 100.TM. Chlorinator." Attention is also directed to Conkling, U.S. Pat. No. 3,779,268, illustrating a regulator valve for a chlorine gas system.
One limitation of some chlorine gas supply systems is the amount of chlorine which can be delivered to the water supply. Use of a single gas cylinder permits the discharge of chlorine gas only at a limited flow rate before frosting of the valve makes the gas regulator valve inoperative.
In many areas, chlorine gas suppliers require that chlorine tanks be emptied completely before they can be returned to the supplier for refilling. Existing gas regulation systems have not provided an effective mechanism for insuring efficient use of all of the chlorine in the tanks. In other areas, chlorine gas suppliers require that chlorine tanks returned for refilling contain a predetermined quantity of chlorine in the tanks. Some gas regulation systems do not provide an effective mechanism for controlling the amount of gas left in the gas supply cylinders.
Another limitation of some chlorine gas systems is that they have not provided an effective and efficient system for switching over from one chlorine supply container to another chlorine supply container once the supply in the first container is exhausted. Further, some gas feed systems do not insure complete use or controlled use of the gas in the first container; other systems require mechanically complex regulator valve assemblies, and are expensive and unreliable.